Question

40 species of animals live in the forest: 7 species more carnivores than ungulates, and 2 species more rodents that carnivores. How many ungulates live in the forest?

Answer 1

Number of ungulates is 8.

Explanation:

C is for carnivores, U is for ungulates, and R is for rodents.

For carnivores: `C=7+U` can be written
For rodents: `R=2+C` can be written.
For rodents, instead of C, you can write the first equation (7+U) yielding
For rodents: `R=2+7+U`

Now you have 3 components for your equation, each component contains U term.

Your final equation is

`40=(7+U) + U + (2+7+U)`

`40= 16 + 3U`

`40-16 = 3U`

`24 = 3U`

`8 = U`

Number of ungulates is 8.

That is your answer. Number of ungulates is 8.